Gangs armed with machetes and shotguns and seeking revenge after reports that Muslims in the mainly Christian southern city of Onitsha had attacked a Christian school poured through the streets of the city, witnesses said, as the death toll from days of Christian-Muslim violence across Nigeria rose to at least 93. Witnesses said they saw at least 20 dead in Onitsha. Thirty people were killed in the city a day earlier. "Major streets are littered with bodies," a resident, Isotonu Achor, said. He said most were Muslims. Other residents said two mosques were burned down. The sectarian violence erupted Saturday in northern Maiduguri, where Muslim protests against cartoons lampooning the Prophet Muhammad turned violent, with 30 churches razed and 18 people killed, mostly Christians. Similar violence followed Monday and Tuesday in another northern city, Bauchi, where witnesses and Red Cross officials said 25 people were killed when Muslim mobs attacked Christians there.